1. Field of the Invention
The present invention relates to a heat sink assembly, and particularly to a heat sink assembly having both internal and external fans.
2. Description of Related Art
Many electronic devices such as central processing units (CPUs) generate a lot of heat. The heat must be efficiently removed from such devices, to ensure normal operation. Conventionally, a heat sink with extruded fins is mounted on an electronic device to remove heat therefrom. Sometimes, a fan is coupled with the heat sink to enhance air convention.
Unfortunately, manufacturing of heat sinks by extrusion limits the height of the fins produced. As electronic devices become more and more powerful, they generate more and more heat during operation. Extruded heat sinks are becoming increasingly unable to provide the levels of heat removal required by contemporary electronic devices. Moreover, fins of most typical heat sinks are arranged in regular linear arrays which unduly obstruct airflow between the fins. Furthermore, single-fan systems are becoming increasingly unable to provide the levels of heat removal required by contemporary electronic devices.
Thus, an improved heat sink assembly which overcomes the above-mentioned problems is strongly desired.
Accordingly, an object of the present invention is to provide a heat sink assembly having enhanced airflow.
A further object of the present invention is to provided a heat sink assembly which removes heat from an electronic device more efficiently.
In order to achieve the objects set out above, a heat sink assembly of the present invention comprises a heat sink, an internal fan, a fan frame and an external fan. The heat sink comprises a base and a fin member attached to the base. The fin member comprises a central portion, and a plurality of fins extending radially from the central portion. A central cavity is defined in the fin member, surrounded by the fins. The internal fan is received in the cavity and supported by the central portion. The fan frame has an opening defined therein, and is mounted on the heat sink. The external fan is mounted on the fan frame such that it covers the opening. The internal fan accelerates airflow from upper portions of the fin member to lower portions of the fin member.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.